This kind of native HTML5 content is key to Microsoft and other phone and tablet makers going forward. As I've blogged previously, IE 9 is a key pillar of Microsoft's tablet/slate push. And Microsoft is looking for native HTML5 apps, not ones powered by plug-ins like Silverlight and Flash -- or Windows Presentation Foundation (WPF) ones that are tied to the Windows client OS -- to populate its app store(s) in the future.

In spite of Microsoft's backing, the contest, Dev Unplugged, isn't limited to apps that work only or best in Internet Explorer (IE) 9. According to the Dev Unplugged rules, the content must render correctly in the Release Candidate (RC) of IE9, the latest Chrome beta and the latest Firefox beta. Submissions must stick to HTML/CSS/JS on the client-side, with no restrictions on the server-side.

The first two categories of content/apps that Microsoft is seeking from devs are games and music. Within these categories are four areas of specialization: Most innovative uses of geo-location, Pinned Sites (an IE 9 feature), Canvas and SVG, and design/UX (user experience).

"We believe that HTML5 and related technologies, in conjunction with faster and faster browsers, finally give developers the tools they need to create experiences that are just as vivid, interactive and high-fidelity as what you have come to expect from native applications without the need for plug-ins. We want to see what you can do unplugged," reads the text on the Dev Unplugged site.

Microsoft has assembled a panel of judges who are considered "experts in HTML5, design and user experience on the web." Microsoft plans to allow "the community" to vote for the top 40 finalists from which the judges will select winners based on "creativity, quality of implementation and fit with the contest theme."

The contest opens on March 1, with the submission gallery opening up to the public for voting on April 5. The submission deadline is May 9, with the winners announced on May 23. The grand prize is $9,000, plus a trip to the Future of Web Apps Conference in Las Vegas on June 27.

Update (March 3): Microsoft isn't the only browser maker to be encouraging the creation of apps and content that don't require plug-ins. Shortly after Microsoft announced this contest, the Khronos Group announced the standardization of WebGL, which delivers 3D graphics support. Apple Google, Mozilla and Opera are backers. Microsoft officials said the company is "always listening to customer feedback," but had nothing to say at this time, as far as Microsoft's plans for adopting WebGL.